1. Field of the Invention
The invention relates generally to devices and methods for reducing and countering the friction forces resulting from the production of fluids.
2. Description of the Related Art
When a stationary object is in the path of fluid flow, it will experience two types of flow-induced forces. Pressure forces are created by integration of pressure that is distributed along the surfaces that are exposed to the pressures. Friction forces are created by the viscous effect exerted by the flow along exposed surfaces. Those forces are normally at one order of magnitude lower than the pressure forces. The net pressure force results from the pressure differential or pressure drop across the object. While the viscous force is always in the same direction as the flow next to the wall of the object, the pressure force including its direction and magnitude is subjected to the changing of the characteristics of the flow field. One typical example is VIV (Vortex-Induced-Vibration) of marine line-like structures. In a flow field, a vortex or a circulation is always related to a low pressure region.
These pressure and friction forces are significant in wells wherein there are high production flow rates. Locks are often used to secure flowmeters and other instrumentation inside production tubing, and these locks can actually become unset and flowed out of the production string by the fluid pressure and friction forces resulting from high flow rates within the production string.